Forward streaming chunks from OpenAIGenerator to FastAPI StreamingResponse

[anhhct]

I'm building a RAG pipeline with Haystack, where I want OpenAIGenerator to generate the reply, and serve the pipeline in a FastAPI endpoint.
The struggle is, Haystack's way of streaming is the OpenAIGenerator component accepts a streaming callback function (via streaming_callback argument when initiate the Generator component). The examples in documentation shows using 'print' function to print the response chunk, which is not what I want (send the response chunk back to client side via FastAPI's StreamingResponse).
The question is, how do I do that?
Hope the question is clear enough.